The 3rd generation partnership project 3GPP has standardized “Support for BroadBand Forum Accesses Interworking” within Rel-11 and is going on with the work within Rel-12.
According to the solution proposed therein, a fixed network access can be used by a 3GPP user equipment UE to access a 3GPP core network, transparently through the fixed network access. Transparency is made by (IP security) tunneling through the fixed network access. The access side between the UE and the fixed network access may comprise e.g. a wireless local area network WLAN or a Home Node-B (H(e)NB). A 3GPP UE may use the access e.g. to access IP multimedia subsystem IMS services offered by the 3GPP network operator.
An IP multimedia subsystem IMS, as standardized by 3GPP, uses user/UE location information provided by the network to the IMS network entities, such as a proxy call server control function P-CSCF. The location information is used e.g. for emergency services, e.g. to locate the user/UE in an emergency situation. The user location information (in case of different 3GPP and 3GPP2 accesses) is provided to P-CSCF by Policy and charging rules function PCRF, typically during a user session establishment, modification and (possibly also) termination.
For some reasons, 3GPP has not standardized a solution in Rel-11 for providing the user location to the IMS network (or in general, to the core network), when the 3GPP UE uses a fixed network access to access 3GPP core network. This prevents the use of location based services in the network, e.g. the essential action by an emergency service centre to locate the user in an emergency situation.
User location information known by the fixed access network cannot be transferred to the 3GPP core network in the same way as within a pure 3GPP access, because the UE uses an IP tunnel over the fixed access network, which prevents the fixed access network elements from inserting user location information into the bearer level signaling between the UE and 3GPP core network.
A permanent/static IP address or address range could obviously be used, at least in theory and through relevant configuration or interpretation, as location information. But IP address of a fixed broadband access user/UE may be either static or dynamic, and address ranges used by the fixed network operator may be changed by the operator in course of time. Consequently, an IP address or address range based location identification may not be reliable or usable.
Further related information can be derived from the following prior art documents:                3GPP TS 23.139 “3GPP System-Fixed Broadband Access Network Interworking; Stage 2”        3GPP TS 23.402 “Architecture enhancements for non-3GPP accesses”        3GPP TS 23.203 “Policy and Charging Control Architecture”        3GPP TS 29.212 “Policy and Charging Control (PCC) over Gx/Sd reference point”        3GPP TS 29.214 “Policy and Charging Control over Rx reference point”        IETF RFC 6320 “Protocol for Access Node Control Mechanism in Broadband Networks”        
However, the current 3GPP specification offers no solution for user location indication to 3GPP core network for the fixed network interworking. This prevents the system e.g. to locate the user for emergency services, when the user accesses 3GPP network via fixed access.